/*
 * Copyright (c) 2008 Princeton University
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Niket Agarwal
 */

#include "mem/ruby/network/garnet-flexible-pipeline/NetworkConfig.hh"
#include "mem/ruby/network/garnet-fixed-pipeline/VCallocator_d.hh"
#include "mem/ruby/network/garnet-fixed-pipeline/Router_d.hh"
#include "mem/ruby/network/garnet-fixed-pipeline/InputUnit_d.hh"
#include "mem/ruby/network/garnet-fixed-pipeline/OutputUnit_d.hh"
#include "mem/ruby/network/garnet-fixed-pipeline/GarnetNetwork_d.hh"

VCallocator_d::VCallocator_d(Router_d *router)
{
        m_router = router;
        m_num_vcs = m_router->get_num_vcs();
        m_vc_per_vnet = m_router->get_vc_per_vnet();
        m_local_arbiter_activity = 0;
        m_global_arbiter_activity = 0;
}

void VCallocator_d::init()
{
        m_input_unit = m_router->get_inputUnit_ref();
        m_output_unit = m_router->get_outputUnit_ref();

        m_num_inports = m_router->get_num_inports();
        m_num_outports = m_router->get_num_outports();
        m_round_robin_invc.setSize(m_num_inports);
        m_round_robin_outvc.setSize(m_num_outports);
        m_outvc_req.setSize(m_num_outports);
        m_outvc_is_req.setSize(m_num_outports);

        for(int i = 0; i < m_num_inports; i++)
        {
                m_round_robin_invc[i].setSize(m_num_vcs);

                for(int j = 0; j < m_num_vcs; j++)
                {
                        m_round_robin_invc[i][j] = 0;
                }
        }

        for(int i = 0; i < m_num_outports; i++)
        {
                m_round_robin_outvc[i].setSize(m_num_vcs);
                m_outvc_req[i].setSize(m_num_vcs);
                m_outvc_is_req[i].setSize(m_num_vcs);

                for(int j = 0; j < m_num_vcs; j++)
                {
                        m_round_robin_outvc[i][j].first = 0;
                        m_round_robin_outvc[i][j].second = 0;
                        m_outvc_is_req[i][j] = false;

                        m_outvc_req[i][j].setSize(m_num_inports);

                        for(int k = 0; k < m_num_inports; k++)
                        {
                                m_outvc_req[i][j][k].setSize(m_num_vcs);
                                for(int l = 0; l < m_num_vcs; l++)
                                {
                                        m_outvc_req[i][j][k][l] = false;
                                }
                        }
                }
        }
}

void VCallocator_d::clear_request_vector()
{
        for(int i = 0; i < m_num_outports; i++)
        {
                for(int j = 0; j < m_num_vcs; j++)
                {
                        if(!m_outvc_is_req[i][j])
                                continue;
                        m_outvc_is_req[i][j] = false;
                        for(int k = 0; k < m_num_inports; k++)
                        {
                                for(int l = 0; l < m_num_vcs; l++)
                                {
                                        m_outvc_req[i][j][k][l] = false;
                                }
                        }
                }
        }
}

void VCallocator_d::wakeup()
{
        arbitrate_invcs(); // First stage of allocation
        arbitrate_outvcs(); // Second stage of allocation

        clear_request_vector();
        check_for_wakeup();
}

bool VCallocator_d::is_invc_candidate(int inport_iter, int invc_iter)
{
        int outport = m_input_unit[inport_iter]->get_route(invc_iter);
        int vnet = get_vnet(invc_iter);
        int t_enqueue_time = m_input_unit[inport_iter]->get_enqueue_time(invc_iter);

        int invc_base = vnet*m_vc_per_vnet;

        if((m_router->get_net_ptr())->isVNetOrdered(vnet))
        {
                for(int vc_offset = 0; vc_offset < m_vc_per_vnet; vc_offset++)
                {
                        int temp_vc = invc_base + vc_offset;
                        if(m_input_unit[inport_iter]->need_stage(temp_vc, VC_AB_, VA_) && (m_input_unit[inport_iter]->get_route(temp_vc) == outport) && (m_input_unit[inport_iter]->get_enqueue_time(temp_vc) < t_enqueue_time))
                        {
                                return false;
                        }
                }
        }
        return true;
}

void VCallocator_d::select_outvc(int inport_iter, int invc_iter)
{
        int outport = m_input_unit[inport_iter]->get_route(invc_iter);
        int vnet = get_vnet(invc_iter);
        int outvc_base = vnet*m_vc_per_vnet;
        int num_vcs_per_vnet = m_vc_per_vnet;

        int outvc_offset = m_round_robin_invc[inport_iter][invc_iter];
        m_round_robin_invc[inport_iter][invc_iter]++;

        if(m_round_robin_invc[inport_iter][invc_iter] >= num_vcs_per_vnet)
                m_round_robin_invc[inport_iter][invc_iter] = 0;

        for(int outvc_offset_iter = 0; outvc_offset_iter < num_vcs_per_vnet; outvc_offset_iter++)
        {
                outvc_offset++;
                if(outvc_offset >= num_vcs_per_vnet)
                        outvc_offset = 0;
                int outvc = outvc_base + outvc_offset;
                if(m_output_unit[outport]->is_vc_idle(outvc))
                {
                        m_local_arbiter_activity++;
                        m_outvc_req[outport][outvc][inport_iter][invc_iter] = true;
                        if(!m_outvc_is_req[outport][outvc])
                                m_outvc_is_req[outport][outvc] = true;
                        return; // out vc acquired
                }
        }
}

void VCallocator_d::arbitrate_invcs()
{
        for(int inport_iter = 0; inport_iter < m_num_inports; inport_iter++)
        {
                for(int invc_iter = 0; invc_iter < m_num_vcs; invc_iter++)
                {
                        if(m_input_unit[inport_iter]->need_stage(invc_iter, VC_AB_, VA_))
                        {
                                if(!is_invc_candidate(inport_iter, invc_iter))
                                        continue;

                                select_outvc(inport_iter, invc_iter);
                        }
                }
        }
}

void VCallocator_d::arbitrate_outvcs()
{
        for(int outport_iter = 0; outport_iter < m_num_outports; outport_iter++)
        {
                for(int outvc_iter = 0; outvc_iter < m_num_vcs; outvc_iter++)
                {
                        if(!m_outvc_is_req[outport_iter][outvc_iter]) // No requests for this outvc in this cycle
                                continue;

                        int inport = m_round_robin_outvc[outport_iter][outvc_iter].first;
                        int invc_offset = m_round_robin_outvc[outport_iter][outvc_iter].second;
                        int vnet = get_vnet(outvc_iter);
                        int invc_base = vnet*m_vc_per_vnet;
                        int num_vcs_per_vnet = m_vc_per_vnet;

                        m_round_robin_outvc[outport_iter][outvc_iter].second++;
                        if(m_round_robin_outvc[outport_iter][outvc_iter].second >= num_vcs_per_vnet)
                        {
                                m_round_robin_outvc[outport_iter][outvc_iter].second = 0;
                                m_round_robin_outvc[outport_iter][outvc_iter].first++;
                                if(m_round_robin_outvc[outport_iter][outvc_iter].first >= m_num_inports)
                                        m_round_robin_outvc[outport_iter][outvc_iter].first = 0;
                        }
                        for(int in_iter = 0; in_iter < m_num_inports*num_vcs_per_vnet; in_iter++)
                        {
                                invc_offset++;
                                if(invc_offset >= num_vcs_per_vnet)
                                {
                                        invc_offset = 0;
                                        inport++;
                                        if(inport >= m_num_inports)
                                                inport = 0;
                                }
                                int invc = invc_base + invc_offset;
                                if(m_outvc_req[outport_iter][outvc_iter][inport][invc])
                                {
                                        m_global_arbiter_activity++;
                                        m_input_unit[inport]->grant_vc(invc, outvc_iter);
                                        m_output_unit[outport_iter]->update_vc(outvc_iter, inport, invc);
                                        m_router->swarb_req();
                                        break;
                                }
                        }
                }
        }
}

int VCallocator_d::get_vnet(int invc)
{
  for(int i = 0; i < RubySystem::getNetwork()->getNumberOfVirtualNetworks(); i++)
        {
                if(invc >= (i*m_vc_per_vnet) && invc < ((i+1)*m_vc_per_vnet))
                {
                        return i;
                }
        }
        ERROR_MSG("Could not determine vc");
        return -1;
}

void VCallocator_d::check_for_wakeup()
{
        for(int i = 0; i < m_num_inports; i++)
        {
                for(int j = 0; j < m_num_vcs; j++)
                {
                        if(m_input_unit[i]->need_stage_nextcycle(j, VC_AB_, VA_))
                        {
                                g_eventQueue_ptr->scheduleEvent(this, 1);
                                return;
                        }
                }
        }
}
